Tea saponin (TS), a kind of biodegradable surfactant, was chosen to improve the accessible solubilization of pyrene and cadmium (Cd) in co-contaminated soils cultivated Lolium multiflorum. TS obviously improved the accessibility of pyrene and Cd for L. multiflorum to accelerate the process of accumulation and elimination of the pollutants. The chemical forms of Cd was transformed from Fe-Mn oxides and associated to carbonates fractions into exchangeable fractions by adding TS in single Cd and pyrene-Cd contaminated soils. Moreover, the chemical forms of pyrene were transformed from associated fraction into bioaccessible fraction by adding TS in pyrene and pyrene-Cd contaminated soils. In pyrene-Cd contaminated soil, the exchangeable fraction of Cd was hindered in the existence of pyrene, and bioaccessible fraction of pyrene was promoted by the cadmium. Besides, in the process of the pyrene degradation and Cd accumulation, the effect could be improved by the elongation of roots with adding TS, and the microorganism activity was stimulated by TS to accelerate the removal of pollutions. Therefore, Planting L. multiflorum combined with adding TS would be an effective method on the phytoremediation of organics and heavy metals co-contaminated soils.

Phosphorus (P) associated with minerogenic particles delivered from watersheds can interfere with the common use of total P (TP) concentration as a trophic state metric in lacustrine systems, particularly proximate to tributary entries, because of its limited bioavailability. The concentration of unavailable minerogenic particulate P (PPₘ/ᵤ), where it is noteworthy, should be subtracted from TP in considering primary production potential and trophic state levels. A first mass balance model for PPₘ/ᵤ is developed and tested here for Cayuga Lake, New York. This is supported by a rare combination of detailed information for minerogenic particle level dynamics for the tributaries and lake, the bioavailability of tributary particulate P (PP), and previously tested hydrothermal/transport and minerogenic particle concentration submodels. The central roles of major runoff events and localized tributary loading at one end of the lake in driving patterns of PPₘ/ᵤ in time and space are well simulated, including (1) the higher PPₘ/ᵤ concentrations in a shallow area (“shelf”) adjoining the inputs, relative to pelagic waters, following runoff events, and (2) the positive dependence of the shelf increases on the magnitude of the event. The PPₘ/ᵤ component of P was largely responsible for the higher summer average TP on the shelf vs. pelagic waters and the exceedance of a TP water quality limit on the shelf. The effective simulation of PPₘ/ᵤ allows an appropriate adjustment of TP values to avoid overrepresentation of potential primary production levels.

The population increase has led to the rise of megacities that generate high levels of pollutants. To examine the temporal and spatial trends, the concentration data of total suspended particles (TSP) and coarse particles (particulate matter (PM)10) from the Rio de Janeiro State Environmental Institute (INEA) collected between 1968 and 2013 were used. To our knowledge, this is the study with the longest time series carried out in South America. The results showed that the TSP concentrations for urban and industrial regions exceeded the suggested limit (80 μg m⁻³) for nearly all years examined. PM10 concentrations remained above or very close to the limit (50 μg m⁻³). In several sites, there was a decrease, along the years, in atmospheric particulate matter concentrations, which may be coupled to improvements of fossil fuels and replacement by less-polluting fuels, such as hydrated alcohol and natural gas. However, in other places, high particulate matter concentrations were observed, which are associated with the infrastructure development in the city and for sporting events. The results show a seasonal trend during the study period, which is characterized by high levels of particulates during the austral wintertime. This trend is related to low rainfall and air mass stagnation. Regarding the daily concentrations observed, a tendency for high concentrations in the early morning and late afternoon was observed in urban regions, due mainly to traffic. In the industrial area, the variation was lower and more dependent on industrial activities than on traffic.

For the purpose of clarifying the chemical nature of fly ashes, the raw fly ashes were collected from the stacks of 17 fixed sources consisting of 15 municipal waste incinerators, a metal melting factory, and a cement plant all of which are located in the western Japan from Nov. 2000 to Jan. 2007. The municipal waste incinerators were successfully classified into four groups in terms of the relative mass ratios between chloride, potassium, and sodium. Sodium, potassium, and calcium were found abundantly in fly ashes collected from all four types of municipal waste incinerators. The theoretical estimation of chlorine form suggested that the form of NaCI, KCl, MgCl, and CaCl₂ accounted for approximately 55 % of total chlorine in raw fly ash. Trace heavy metals (i.e., Zn, Mn, Pb, Cu, Cr, Ni, and V) were preferentially enriched in the ambient PM₂.₅ which was strongly influenced by regional stationary sources (including municipal waste incinerators). The water-soluble OC to TC fraction in the fly ashes of municipal waste incinerator, metal furnace, and cement plant was estimated as 56.8, 79.0, and 89.6 %, respectively.

Iron (Fe) nutrition status and activity of Fe-dependent enzymes is suggested to be affected by air pollution. This study was aimed to investigate changes in leaf Fe, zinc (Zn), chlorophyll (a, b), and carotenoid concentration and activity of catalase (CAT) and peroxidase (POX) in the leaves of maple (Acer negundo L.) with distance from two major sources of air pollution, i.e., Oil Refinery of Shiraz (ORS) operations and urban traffic of Imam Hossein square (AS) in Shiraz, Iran. By increasing the distance from the ORS, Fe, Zn, and chlorophyll concentration in the maple leaves increased. These changes were associated with lower intensity of chlorosis symptoms on the leaves of maple trees with distance from the ORS. Leaf activity of CAT increased with increasing distance from the ORS. Changes in concentration of carotenoids and activity of POX did not follow a distinct trend with distance from both pollution sources. No regular pattern was observed for changes in the measured parameters with distance from the urban traffic of Imam Hossein square (AS), as another major source of air pollution in the studied region. This was due to irregular changes in the concentrations of air pollutants across the sampling pathway. According to the results, significant impairment in Fe nutritional status is expected for plants exposed to the air pollution, although further studies are needed to clarify the physiological reasons of Fe chlorosis under air pollution stress.

The Orcia River basin lies north of the Mt. Amiata mining district and may receive potentially harmful/toxic elements such as mercury (Hg) and arsenic (As) therefrom. The Orcia River eventually flows to the Ombrone River, which in turn flows to the Tyrrhenian Sea. The analysis of stream sediments collected in the Orcia River and its main tributaries, as well as in the Ombrone River, indicates moderate concentrations of both Hg and As (median values, Hg 118 μg/kg and As 5.25 mg/kg), rarely exceeding Italian environmental quality standards. Exceptionally high values for both elements are observed only in close proximity to the former Pietrineri Hg mine (Hg 195 mg/kg and As 35 mg/kg). Travertine and unconsolidated deposits associated with thermal springs in the area generally exhibit low Hg concentrations (4–320 μg/kg), with a significant exception of 23 mg/kg at Bagni San Filippo. Arsenic concentration in the same deposits is more variable with a peak level of 358 mg/kg. Surface waters collected at the same sites as stream sediments show Hg and As concentrations below the Italian mandatory limits for drinking waters (1 μg/L for Hg and 10 μg/L for As). Likewise, in thermal springs, Hg concentrations are low, whereas As concentrations are relatively high (up to 23.4 μg/L), which is in agreement with previous studies. At present, the input of toxic elements from the mining district into the Orcia and Ombrone watersheds is lower than inputs documented in the Paglia and Tiber catchments south of Mt. Amiata and does not pose an immediate environmental threat. However, the possible remobilization of Hg-contaminated sediments during flash flood events cannot be dismissed.

Mercury (Hg), aside from having high toxicity, is characterized by its ability to biomagnify in the marine trophic chain. This is an important problem especially in estuaries, or in the coastal zone, particularly near the mouths of large rivers. This study was conducted in the years 2001–2011, in the coastal zone of the Baltic Sea near to the mouth of the River Vistula, which is the second biggest river discharging into the Baltic. Mercury concentration was measured in the tissues and organs of cod, flounder, herring, seals (living in the wild and in captivity), great black-backed gulls, and African penguins from Gdańsk Zoo, and also in human hair. Penguins and seals at the seal sanctuary in Hel were fed only herring. In marine birds and mammals and in the pelagic herring, the highest Hg concentration was observed in the kidney and in the liver, while in cod and flounder (located on a higher trophic level) the muscles were the most contaminated with mercury. In gray seals living in the seal sanctuary, Hg concentration in all analyzed tissues and organs except the kidneys was lower in comparison with seals living in the wild. The comparatively small share of fish in the diet of local Polish people and their preference towards the consumption of herring contributed to low concentration of Hg in their hair. The protective mechanisms related to detoxification and elimination of mercury were shown to be more effective in the seals than in the penguins, despite the former consuming around 10 times more food per day.

The overall purpose of this work was to evaluate the treatment system performance of sequential hybrid bioreactors, one without aeration and another with intermittent aeration, in the bioremoval of Cr(VI) and total chromium and in the removal of total organic carbon (TOC). The saturation kinetic curves were studied with initial concentrations of Cr(VI) of 80, 120 and 150 mg L⁻¹. A reference test was performed before adding chromium to the system, with the intention of checking the influence of the presence of chromium on the TOC removal. During the bioreactor regeneration, the chromium removal was evaluated, after each kinetic studied. For kinetics with 80 mg L⁻¹ of Cr(VI), the results showed that after 600 h of operation, there was no saturation of bioreactors, yielding 87 % overall removal of Cr(VI) and 62 % chromium total. For initial concentrations of Cr(VI) of 120 and 150 mg L⁻¹, only the non-aerated bioreactor reached saturation after 228 and 216 h of operation, respectively. In regeneration, it was found in all the assays performed that the chromium concentration at the outlet of the bioreactor became almost zero at a maximum of 72 h of operation. In the blank test, the TOC removal achieved was 64 %, while in the three tests in the presence of chromium, this was approximately 55 % (80 mg L⁻¹), 41 % (120 mg L⁻¹) and 31 % (150 mg L⁻¹). After cell lysis by ultrasound, it was found that the chromium concentration retained inside there was lower than the concentrations present in the environment.

The objective of this study was to assess the impact of metal contamination on microbial functional diversity and enzyme activity in forest soils. This study involved the evaluation of the influence of the texture, carbon content and distance to the source of contamination on the change in soil microbial activity, which did not investigate in previous studies. The study area is located in southern Poland near the city of Olkusz around the flotation sedimentation pond of lead and zinc at the Mining and Metallurgical Company “ZGH Bolesław, Inc.”. The central point of the study area was selected as the middle part of the sedimentation pond. The experiment was conducted over a regular 500 × 500-m grid, where 33 sampling points were established. Contents of organic carbon and trace elements (Zn, Pb and Cd), pH and soil texture were investigated. The study included the determination of dehydrogenase and urease activities and microbial functional diversity evaluation based on the community-level physiological profiling approach by Biolog EcoPlate. The greatest reduction in the dehydrogenase and urease activities was observed in light sandy soils with Zn content >220 mg · kg⁻¹ and a Pb content > 100 mg · kg⁻¹. Soils with a higher concentration of fine fraction, despite having the greatest concentrations of metals, were characterized by high rates of Biolog®-derived parameters and a lower reduction of enzyme activity.

Carbamazepine is one of the pharmaceutical compounds frequently detected in the receiving waters and water bodies. The main objective of this study was to develop a quadratic model to predict carbamazepine (CBZ) photocatalytic removal through a response surface methodology. A factorial plan (linear model; 2⁴ experiments) was used to determine the contribution of individual factors (pH, CBZ concentration, photocatalyst concentration, and treatment time) and interactions among the factors. Pollutant concentration and treatment time were found to be the most important parameters influencing the oxidation rate, with respective contributions of 19.22 and 71.55 %. Central composite methodology was then applied to determine the optimal experimental parameters for CBZ oxidation. The highest percentage of CBZ removed was 94.67 ± 0.51 %, recorded using a pH of 5, a minimal CBZ concentration of 10 mg/L, a photocatalyst concentration of 1.14 g/L, and a treatment time of 90 min. The effects of different anions (NO₃ ⁻ and SO₄ ²⁻) and cations (Cu²⁺, Cr³⁺, Zn²⁺) were also studied. Copper was found to have both catalytic and inhibitory effects on CBZ removal rate.